AUSTIN (KXAN) — As the summer boating season ramps up, parks officials are urging boaters to take steps to prevent the further spread of zebra mussels across the state.

The invasive species was first detected in Lake Texoma, north of Dallas, in 2009. Now, a total of 31 lakes are infested, according to the Texas Parks and Wildlife Department.

Zebra mussels have also been detected in a further four lakes and are suspected in one more.

Most of the infested lakes are clustered in central and north Texas. Last month, another lake was added to the infected list: Hords Creek Lake in Coleman County, south of Abilene.

A single zebra mussel was found attached to dam infrastructure in the lake in April, TPWD said. Follow-up surveys found the presence of a reproducing population in the lake.

There is one success story: Lake Waco. Zebra mussels were first detected in the lake in 2014, but by 2021, the lake was declared free of the species. The zebra mussels had been eradicated.

How to prevent zebra mussels spread in Texas

Zebra mussels are often spread from lake to lake on or in boats. TPWD says the mussels attach to boats or anything left in the water, like anchors, and can survive for days out of the water. The larvae are not visible to the naked eye, so oftentimes boaters don’t know they’re transporting them.

“Unfortunately, zebra mussels have now spread to 35 Texas lakes, but there are far more lakes in Texas that still haven’t been invaded and are at risk,” said Brian Van Zee, regional director for TPWD Inland Fisheries. “Each boater taking steps to clean and drain their boat before leaving the lake — and allowing compartments and gear to dry completely when they get home — can make a big difference in protecting our Texas lakes.”

TPWD encourages boaters to clean, drain and dry boats and gear before moving between lakes. This includes removing all plants, mud and debris. Everything should be allowed to dry completely for at least a week, if possible.

Boats that have been stored in lakes with zebra mussels are likely infested and pose “an extremely high risk for transporting these invasive species to a new lake,” TPWD said. Boaters can call the department at 512-389-4848 for guidance before moving the boat.